Guide wire

ABSTRACT

A guide wire is comprised of a flexible elongate wire body. The wire body has a plurality of protruding portions n the external surface and recessed portions between the adjacent protruding portions. The protruding portions possess a friction coefficient smaller than that of the recessed portions.

This application claims priority under 35 U.S.C. §119(e) to U.S.Provisional Application No. 61/078,096 filed on Jul. 3, 2008, the entirecontent of which is incorporated herein by reference. This applicationalso claims priority under 35 U.S.C. §119(a) based on JapaneseApplication No. 2008-171827 filed on Jun. 30, 2008, the entire contentof which is incorporated herein by reference.

TECHNOLOGICAL FIELD

The present invention relates generally to guide wires and moreparticularly to a guide wire used to introduce a catheter into a bodycavity such as e.g. a blood vessel, a bile duct, etc.

BACKGROUND DISCUSSION

A guide wire is used to guide a catheter to treat or diagnose vascularstenosis in a cardiac artery or in a peripheral artery such as a limb orthe like. The guide wire used for such procedure is inserted to thevicinity of a vascular stenosis site or a target site together with acatheter with the distal end of the guide wire allowed to project fromthe distal end of the catheter. In this state, the catheter is shiftedalong the guide wire to guide the distal end portion of the catheter tothe vicinity of the vascular stenosis site.

The blood vessel requiring the above-mentioned procedure has an induratestenosis site, a partially steeply bending flexion or the like.Therefore, the guide wire may be sometimes hard to pass through. Becauseof this, the guide wire used to guide the catheter into the blood vesselrequires not only adequate flexibility and restoring performance forbending, but also pushability and torque transmissibility fortransmitting the operation of the proximal end portion to the distal endside, and further anti-kink performance (anti-bending performance) andthe like. (The pushability and torque transmissibility are genericallyreferred to as “operability”.)

To improve the operability (pushability) of the guide wire, the guidewire has been covered on an outer surface with a material adapted tomake satisfactory the sliding performance with the catheter innersurface. An example is the guide wire described in Japanese PatentLaid-Open No. Hei 5-168717, referred to as Patent Document 1hereinafter. The guide wire described in Patent Document 1 is such thata distal portion is coated with a hydrophilic resin and a proximalportion which is to be handled is covered with a fluorinated resindifferent from that for its distal end side portion in order to improvea grip force (gripping force) encountered when the guide wire is grippedat its hand portion. However, even if the portion to be handled iscovered with the fluorinated resin, since the fluorinated resin surfacehas a relatively low friction coefficient relative to a finger, the gripforce is not increased. That is to say, there arises a problem in thatsince the portion to be handled is slippery, a pushing and turning forceis hard to transmit depending upon a to-be-inserted site or a catheterso that operability is not high.

There is a guide wire that is covered with a hydrophilic resin, whereinthe distal end side portion of its covering layer is removed and aspiral slip-prevention member is provided at such a removed portion. Anexample is disclosed in Japanese Patent Laid-Open No. Hei 7-328126,referred to as Patent Document 2 hereinafter. However, although theguide wire described in Patent Document 2 exhibits a grip force whenoperated by gripping the portion provided with the slip-preventionmember, if such a portion is inserted into the lumen of the catheter,just then the slip-prevention member functions to lower slidingperformance. If the slip-prevention member is provided only at theproximal end of the guide wire, the intermediate portion of the guidewire, i.e., a portion not provided with the slip-prevention member willbe gripped during insertion. Therefore, the hydrophilic resin (thecovering layer) functions to lower the grip force, so that unnecessarytime will be spent for the insertion.

There is also a guide wire in which a wire is spirally wound to formconcavity and convexity on a jacket surface (a covering layer) made ofPTFE or the like and thereafter the convexity is subjected tohydrophilic or hydrophobic coating. An example is disclosed inInternational Application Publication No. WO 05/44358 referred to asPatent Document 3 hereinafter. Although the guide wire described inPatent Document 3 improves sliding performance, since the material witha low friction coefficient such as PTFE or the like is used as thematerial forming the jacket, an improvement in grip force cannot beexpected. Further, the step for forming concavity and convexity iscomplicated and it is difficult to form uniform concavity and convexity.

SUMMARY

A guide wire disclosed here is comprised of a flexible elongate wirebody. The wire body has a protruding portion formed on the externalsurface of the wire body, and non-protruding portion between theadjacent protruding portion. The protruding portion is formed of amaterial having a friction coefficient smaller than that of a materialforming the non-protruding portion.

The top of the protruding portion is preferably formed of a fluorinatedresin material.

Also, it is preferable that the top of the protruding portion isrounded.

The bottom of the non-protruding portion has a portion extendinglinearly along a longitudinal direction of the wire body as viewed inlongitudinal cross-section.

According to another aspect, a guide wire including a flexible elongatewire body, wherein the wire body has a protruding portion on itsexternal surface and the non-protruding portion located between theadjacent protruding portion. During use of the guide wire, slidingresistance encountered when a top of the protruding portion comes intomain contact is smaller than that encountered when also a bottom of thenon-protruding portion comes into contact, so that the top is moreslippery than the bottom.

In the guide wire disclosed here, it is preferred that an occupancy ofthe protruding portion on the external surface be smaller than that ofthe non-protruding portions. Also, it is preferred that the bottom ofthe non-protruding portion be roughened.

In the guide wire disclosed here, the protruding portion is preferablyformed of at least one linear member, and can be configured in a spiralor ring-shaped manner.

The protruding portion can be formed of two spirally extending linearmembers whose spiral winding directions are opposite to each other.

According to other possibilities, the linear member can be formed tolinearly extend along the longitudinal direction of the wire body.

Also, in the guide wire disclosed here, the protruding portion can becomposed of a plurality of the linear members, with the linear membersarranged at given intervals along a circumferential direction of theexternal surface.

According to another variation, the protruding portion can be arrangedin a scattered manner.

In the guide wire disclosed here, it is preferred that the protrudingportion has a high-density part and a low-density part located closer tothe proximal end side than the high-density part, with the high-densitypart and the low-density part being different in arrangement densityfrom each other.

The wire body preferably has a tapered section gradually reduced inouter diameter toward the distal end and an outer diameter-uniformsection provided at a proximal end of the taper section and having anuniform outer diameter.

In the guide wire disclosed here, it is preferred that the high-densitypart is spanned from the tapered section to the outer diameter-uniformsection. It is also preferable that the low-density part be located atthe outer diameter-uniform section.

In the guide wire disclosed here, the protruding portion can be formedby applying a liquid material to the wire body and then drying it.

According to the disclosure here, when the guide wire is inserted intothe tube-cavity such as, for example, the lumen of a catheter or thelike, a portion located (inserted) in the tube-cavity of the guide wireis such that the respective protruding portion low in frictioncoefficient come into main contact with the inner wall partitioning thetube-cavity but the non-protruding portion high in friction coefficientis prevented from coming into contact with the inner wall. Thus, whenthe guide wire is operatively shifted along the axial direction orturned around its axis, the protruding portion will be slid along theinner wall, which exhibits satisfactory sliding performance.

At a gripped portion of the guide wire, for example, a finger is able toenter (be positioned in) the non-protruding portion. The front surfaceof the finger comes into contact with the bottom of the non-protrudingportion high in friction coefficient rather than comes into abutmentagainst the respective protruding portion low in friction coefficient.Thus, the grip force (the gripping force) can reliably be prevented fromlowering when the guide wire is operatively shifted or turned, so thatthe operating force (the pushability, torque) at that time is reliablytransmitted to the distal end of the guide wire. It is an objectdisclosed here to provide a guide wire that can reliably prevent a gripforce (gripping force) from lowering when the guide wire is operativelygripped while exhibiting satisfactory sliding performance within atube-cavity such as a lumen of a catheter or the like.

According to another aspect, a guide comprises an elongated flexiblewire body comprising a distal end portion and a proximal end portion, afirst constant diameter section at which the outer diameter of theelongated flexible wire body is a constant outer diameter, a secondconstant diameter section at which the outer diameter of the elongatedflexible wire body is a constant outer diameter less than the constantouter diameter of the first constant diameter section, and a taperedsection at which the outer diameter of the elongated flexible wire bodyvaries from the constant outer diameter of the first constant diametersection to the constant outer diameter of the second constant diametersection. The tapered section is positioned axially between the firstconstant diameter section and the second constant diameter section, andthe first constant diameter section is positioned distally of the secondconstant diameter section. The wire body also comprises a plurality ofradially outward protruding portions spaced apart from one another. Theprotruding portions extend further radially outwardly than portions ofthe outer surface of the flexible wire body surrounding the protrudingportions so that recessed portions exist between adjacent protrudingportions. The guide wire thus possesses an undulating outermost surfaceby virtue of the protruding portions and the recessed portions. Theprotruding portions are located in the first constant diameter section,the tapered section, and the second constant diameter section, and theprotruding portions have an outer surface made of a material possessinga friction coefficient smaller than the friction coefficient of materialforming the outer surface of the flexible wire body in the recessedportions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial longitudinal cross-sectional view illustrating afirst embodiment of a guide wire disclosed here.

FIG. 2 is an enlarged longitudinal cross-sectional view of the area [A]surrounded by a chain line in FIG. 1.

FIG. 3 is an enlarged longitudinal cross-sectional view of the area [B]surrounded by a chain line in FIG. 1.

FIG. 4 is an enlarged longitudinal cross-sectional view of the area [C]surrounded by a chain line in FIG. 1.

FIG. 5 is a partial longitudinal cross-sectional view illustrating asecond embodiment of the guide wire disclosed here.

FIG. 6 is a partial longitudinal cross-sectional view illustrating athird embodiment of the guide wire disclosed here.

FIG. 7 is a partial longitudinal cross-sectional view illustrating afourth embodiment of the guide wire disclosed here.

FIG. 8 is a partial longitudinal cross-sectional view illustrating afifth embodiment of the guide wire disclosed here.

FIG. 9 is a partial longitudinal cross-sectional view illustrating asixth embodiment of the guide wire disclosed here.

FIG. 10 is an enlarged longitudinal cross-sectional view illustrating aseventh embodiment of the guide wire disclosed here.

FIG. 11 is a graph showing respective friction coefficients of arecessed portion and a protruding portion of the guide wire illustratedin FIG. 1.

FIG. 12 is an explanatory view illustrating a state of a torque test.

FIG. 13 is an explanatory view illustrating another state of a torquetest.

FIG. 14 is an explanatory view illustrating another state of a torquetest.

DETAILED DESCRIPTION

FIGS. 1-4 illustrate one embodiment of a guide wire disclosed here. FIG.11 is a graph showing respective friction coefficients of a protrudingportion and a recessed portion of the guide wire embodiment illustratedin FIGS. 1-4. In FIGS. 1-4, the right and left are referred to as “theproximal end” and “the distal end,” respectively. This also applies tothe other embodiments illustrated in FIGS. 5-10 and described in moredetail below. In addition, to facilitate an understanding, FIGS. 1 to 10illustrate the guide wire shortened in the longitudinal length andexaggerated in diameter. Thus, the ratio between the longitudinal lengthand the diameter as illustrated is different from the actual ratio.

The guide wire 1A illustrated in FIG. 1 is a guide wire for catheterinserted into an inner cavity (lumen) 201 of a catheter 200 (includingan endoscope) during use. The guide wire 1A includes an elongate wirebody 10 and a distal end member 4. The wire body 10 is composed of afirst wire 2 disposed on the distal end side and a second wire 3disposed on the proximal end side of the first wire 2. The first wire 2and the second wire 3 are joined together (connected to each other)preferably by welding. Although not particularly restrictive, theoverall length of the guide wire 1A is preferably about 200 to 5000 mm.

The first wire 2 is made of a flexible or elastic core (wire rod) 20.Although not restrictive, the length of the first wire 2 is preferablyabout 20 to 1000 mm.

In the present embodiment, the first wire 2 includes: a large diametersection 21 with a substantially uniform outer diameter constituting aconstant diameter section; a small diameter section 23, constitutinganother constant diameter section, located closer to the distal end thanthe large diameter section 21 and having an outer diameter smaller thanthat of the large diameter section 21; and a tapered section 22 locatedbetween the large diameter section 21 and the small diameter section 23so as to gradually decrease in outer diameter in the distal enddirection. The sections are arranged in the order of the small diametersection 23, the tapered section 22 and the large diameter section 21from the distal end side of the first wire 2 toward the proximal endside.

The small diameter section 23 and the large diameter section 21 areformed via the tapered section 22 and so the first wire 2 can graduallybe reduced in rigidity (bending rigidity, torsional rigidity) toward thedistal end. Consequently, the guide wire 1A can have satisfactoryflexibility and narrowed-area passability at its distal end portion soas to improve following performance and safety with respect to a bloodvessel, etc., and help prevent bending and the like.

The taper angle (the reduction ratio of the outer diameter) of thetapered section 22 may be constant along the wire-longitudinal directionor may partially vary in the longitudinal direction. For example, thetapered section 22 may be formed such that a portion having a relativelylarge taper angle (the reduction ratio of the outer diameter) and aportion having a relatively small taper angle are alternately repeated aplurality of times.

The proximal end side portion of the first wire, i.e., the largediameter portion 21, is constant up to the proximal end of the firstwire 2.

The distal end (distal end face) of the second wire 3 is joined(connected) to the proximal end (proximal end face) of the first wire 2(the distal end of the large diameter section 21) preferably by welding.The second wire 3 has a flexible or elastic core (wire rod) 30.

Although not limited in this regard, examples of a welding methodbetween the first wire 2 (the core 20) and the second wire 3 (the core30) include friction pressure welding, laser spot welding, and buttresistance welding such as butt seam welding. Because it providesrelative simplicity and high-joint strength, the butt resistance weldingis particularly preferable.

In the present embodiment, the second wire 3 includes: a large diametersection (an outer diameter uniform section) 31 having a substantiallyuniform outer diameter; a small diameter section 33 located closer tothe distal end than the large diameter section 31 and having an outerdiameter smaller than that of the large diameter section 31; and atapered section 32 between the large diameter section 31 and the smalldiameter section 33, and possessing a gradually reduced outer diametertoward the distal end. These sections of the second wire 3 are arrangedin the order of the small diameter section 33, the tapered section 32and the large diameter section 31 from the distal end side of the secondwire 3 toward the proximal end side. The outer diameter of the distalend portion of the small diameter section 33 is substantially equal tothat of the large diameter section 21 of the first wire 2. Thus, whenthe proximal end (proximal end face) of the large diameter section 21 ofthe first wire 2 is joined to the distal end of the small diametersection 33 of the second wire 3, a step due to differences in outerdiameter between the wires 2, 3 will not occur on the outercircumference of the joint portion (the joint surface) 6. Thus, acontinuous smooth surface exists at the joint.

The second wire 3 is such that the small diameter section 33 and thelarge diameter section 31 are formed via the tapered section 32.Therefore, the second wire 3 can gradually be reduced in rigidity(bending rigidity, torsional rigidity) toward the distal end.Consequently, the guide wire 1A can have satisfactory flexibility at thesecond wire 3, similar to the first wire 2, so as to improve followingperformance and safety with respect to a blood vessel, etc., and preventbending and the like. Further, since physical characteristics,especially, elasticity smoothly varies from the second wire 3 to thefirst wire 2, even the front and rear of the joint portion (jointsurface) 6 of both the wires 2, 3 can exhibit satisfactory pushabilityand torque transmissibility, thereby improving anti-kink performance.

The large diameter section 31 of the second wire 3 has an outer diametergreater than the outer diameter (the maximum outer diameter of the firstwire 2) of the large diameter section 21 of the first wire 2. The outerdiameter of the large diameter section 31 may be e.g. 1.02 to 5 timesthat of the large diameter section 21. In addition, the proximal end 311of the large diameter section 31 is rounded.

The taper angle (the reduction ratio of the outer diameter) of thetapered section 32 may be constant along the wire-longitudinal directionor may partially change in the longitudinal direction. For example, thetapered section 32 may be formed such that a portion having a relativelylarge taper angle (the reduction ratio of the outer diameter) and aportion having a relatively small taper angle are alternately repeated aplurality of times. A plurality of such taper sections may be providedalong the wire-longitudinal direction.

Although not particularly restrictive, the length of the second wire 3is preferably about 20 to 4800 mm, more preferably about 1400 to 3000mm.

The average outer diameter of the first wire 2 is smaller than that ofthe second wire 3. Therefore, the guide wire 1A is such that the firstwire 2, i.e., its distal end side, is relatively quite flexible and thesecond wire 3, i.e., its proximal end side, is relatively highly rigid.Thus, the flexibility of the distal end portion and excellentoperability (pushability, torque transmissibility, etc.) can be combinedtogether.

The constituent material of the wire rod 20 of the first wire 2 and ofthe wire rod 30 of the second wire 3 is not particularly restrictive aslong as it is flexible. Examples of the constituent material includevarious metal materials such as stainless steel (e.g., SUS304, SUS303,SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444,SUS429, SUS430F, SUS302, and the other SUS materials), a piano wire, acobalt-based alloy, and a pseudoelastic alloy (including a superelasticalloy). Among them, the pseudoelastic alloy (including a superelasticalloy) is particularly preferred, and the superelastic material is morepreferred.

A superelastic alloy is relatively flexible, has restoring performanceand is less prone to have bending tendency. Therefore, for example, ifthe first wire 2 is made of a superelastic alloy, the guide wire 1A hassufficient flexibility and restoring performance for bending at itsdistal end portion. Thus, a capability of following a complicatedlycurving and bending blood vessel or the like is improved to provide moreexcellent operability. In addition, even if the first wire 2 isrepeatedly subjected to curving and bending deformation, it does notexhibit bending tendency because of the inherent restoring performanceof the first wire 2. Thus, it is possible to prevent the deteriorationof operability resulting otherwise from the first wire 2 being subjectedto bending tendency during the use of the guide wire 1A.

A cobalt-based alloy formed into a wire has a high degree of elasticityand an appropriate elastic limit. Thus, the wire made of a cobalt-basedalloy has excellent torque transmissibility and rarely causes a problemsuch as buckling or the like. Any cobalt-based alloy may be used as longas it contains Co as a constituent element. However, a cobalt-basedalloy containing Co as a chief ingredient (Co-based alloy: alloy havinga highest rate of content of Co in weight-ratio among elementsconstituting the alloy) is preferable. A Co—Ni—Cr-based alloy may morepreferably be used. Use of the alloys having such compositions makes theeffect described above further remarkable. The alloys having suchcompositions have a high-elastic coefficient and can be cold-formed,though having a high elastic limit. Having the high elastic limit, thealloy having such compositions can reduce its diameter whilesufficiently preventing the occurrence of buckling. Consequently, it canhave flexibility and rigidity sufficient to be inserted into a desiredsite.

Examples of a CO—Ni—Cr-based alloy include an alloy having a compositionof 28 to 50 wt % Co-10 to 30 wt % Ni-10 to 30 wt % Cr-remnant Fe; and analloy whose part is substituted by another element (substitutionelement). Inclusion of a substitution element exhibits an inherenteffect depending on its type. For example, the strength of the secondwire 3 can be further increased by containing at least one selected fromthe group consisting of e.g. Ti, Nb, Ta, Be and Mo as a substitutionelement. Incidentally, if an element other than Co, Ni and Cr iscontained, it is preferred that its content (of the overall substitutionelement) be 30 wt % or less.

A part of Co, Ni and Cr may be substituted by another element. Forexample, Mn can be substituted for a part of Ni. This can furtherimprove workability. Mo and/or W can be substituted for a part of Cr.This can further improve an elastic limit. Among Co—Ni—Cr-based alloys,a Co—Ni—Cr—Mo-based alloy containing Mo is particularly preferable.

The core 20 of the first wire 2 and the core 30 of the second wire 3 maybe composed of respective different materials. However, in the presentembodiment, they are made of the identical metal material or of the sametype metal material (the phrase “same type metal material” means thatthe cores are made of alloys in which the material constituting thelargest percentage content in each is the same). This can increase thejoint strength of the joint portion (welded portion) 6. Thus, althoughthe outer diameter of the joint portion 6 is small, separation or thelike will not occur and so superior torque transmissibility isexhibited.

In this case, each of the first wire 2 (the core 20) and the second wire3 (the core 30) may preferably be made of the superelastic alloysdescribed above, more preferably a Ni—Ti-based alloy among them. Thus,the wire body 10 can ensure superior flexibility on the distal end sidefrom the joint portion 6 and sufficient rigidity (bending rigidity,torsional rigidity) on the proximal end side portion of the wire body10. Consequently, while providing superior pushability and torsionaltransmissibility to ensure satisfactory operability, the guide wire 1Aprovides satisfactory flexibility and restoring performance on thedistal end side to improve a following capability and safety for a bloodvessel, a bile duct and a pancreatic duct.

The first wire 2 and the second wire 3 may be made of differentmaterials. In such a case, the first wire 2 is preferably made of asuperelastic alloy, more preferably a Ni—Ti-based alloy. In addition,the second wire 3 is preferably made of the stainless steel describedabove.

Alternatively, the first wire 2 and the second wire 3 may be made ofpseudoelastic alloys or stainless steel alloys different from each otherin metal composition and in physical characteristic.

The above-description describes a construction in which the first wire 2and the second wire 3 are joined together. However, a wire made of asingle member without the joint portion may be applicable. In such acase, examples of the constituent material of the wire include the samematerials as described earlier, particularly preferably stainless steel,a cobalt-based alloy and a pseudoelastic alloy.

As illustrated in FIG. 1, a distal end member 4 is disposed on the outercircumference of the distal end portion of the wire body 10. The distalend member 4 covers a portion of the first wire 2 from the distal end ofthe first wire 2 to the middle portion or intermediate region of thelarge diameter section 21. In the illustrated embodiment, the distal endmember 4 covers less than the entire length of the first wire member.The installation or application of the distal end member 4 reduces thecontact area of the external surface of the wire body 10 with the innerwall 202 of the catheter 200 or with a living body surface. This canreduce sliding resistance, with the result that the operability of theguide wire 1A is improved.

The distal end member 4 is configured as a circular cylinder possessinga constant outer diameter in the longitudinal direction of the wire body10. The distal end member 4 has a distal end 41 and a proximal end 42which are both rounded. By virtue of the rounded distal end 41 of thedistal end member 4, when the guide wire 1A is inserted into a bodycavity such as a blood vessel, damage to its inner wall can moreeffectively be prevented to enhance safety.

The distal end member 4 is preferably made of a flexible material (asoft material, an elastic material). Examples of such a flexiblematerial include polyolefin such as polyethylene and polypropylene,polyvinyl chloride, polyester (PET, PBT, etc.), polyamide, polyimide,polyurethane, polystyrene, a silicone resin, thermoplastic elastomersuch as polyurethane elastomer, polyester elastomer and polyamideelastomer, rubber materials such as latex rubber and silicon rubber, anda complex material combining two or more among them. In particular ifthe distal end member 4 is made of the thermoplastic elastomer orvarious rubber materials described above, the flexibility of the distalend portion of the guide wire 1A is more improved. Therefore, when theguide wire 1A is inserted into a blood vessel or the like, a bloodvessel inner wall or the like can reliably be prevented from beingdamaged to provide an extremely high degree of safety. In addition, suchresin materials are superior in adhesion to a superelastic alloyrepresented by the Ni—Ti alloy mentioned above. Thus, the distal endmember 4 is reliably secured to the first wire 2. In the illustratedembodiment, the distal end member 4 is in direct contact with the firstwire member 2 (i.e., the inner surface of the distal end member 4directly contacts the outer surface of the first wire member 2).

Although not particularly limited in this regard, the length of thedistal end member 4 is preferably about 5 to 700 mm, more preferablyabout 50 to 500 mm.

Fillers (particles) made of a material with contrast performance(radiopaque material, etc.) may be scattered in the distal end member 4to form a contrast portion.

As illustrated in FIG. 1, the external surface of the distal end member4 is covered by a covering layer 5. This covering layer 5 is formed bycoating the outer surface of the distal end member 4 with a hydrophilicmaterial. The hydrophilic material becomes wet to cause lubricatingability, which reduces the friction (friction resistance) of the guidewire 1A to improve sliding performance. Thus, the operability of theguide wire 1A is improved.

Examples of the hydrophilic material include: a cellulosichigh-molecular material, polyethylene oxide high-molecular material,maleic acid anhydride high-molecular substance (e.g. maleicacidanhydride copolymer such as methylvinylether-maleicacidanhydride),acrylamide-based high-molecular material (e.g. polyacrylamide, blockcopolymer of polyglycidylmethacrylate-dimethylacrylamide (PGMA-DMAA),water-soluble nylon, polyvinyl alcohol, and polyvinylpyrrolidone.

Such hydrophilic materials exhibit lubricating ability resulting frommoistness (water absorption) in many cases to reduce the frictionalresistance (sliding resistance) with the inner wall 202 of the catheter200 used together with the guide wire 1A. Thus, the sliding performanceof the guide wire 1A can be improved to provide more satisfactoryoperability of the guide wire 1A in the catheter 200.

FIGS. 2 and 3 illustrate that the second wire 3 is comprised of an innerlayer 7, an outer layer 8 and a linear member (a first linear portion)9A formed (laminated) in this order on the outer circumferential side ofthe core 30.

The inner layer 7 is applied directly on the outer circumference of thecore 30. The inner layer 7 is formed of a material containing resin andpigment.

Although not particularly restrictive, examples of the resin material inthe inner layer 7 preferably include a fluorinated resin material. Theinner layer 7 contains two kinds of fluorinated resin materialsdifferent in composition from each other. The two kinds of resinmaterials can be such that, for example, one is polytetrafluoroethylene(PTFE) and the other is fluorinated ethylene propylene (FEP).

Although the pigment in the inner layer 7 may be any of inorganicpigment and organic pigment, inorganic pigment is preferable in view ofthermal resistance during the formation of the inner layer 7. Usableexamples of the inorganic pigment include carbon black, isinglass,titanium dioxide, nickel titanium yellow, Prussian blue, Milori blue,cobalt blue, ultramarine, and Viridian. One kind of pigment may be usedalone, but two or more may be used together (specially mixed). Althoughnot particularly restrictive, the average diameter of the pigment ispreferably e.g. 0.3 to 5 μm, more preferably 0.5 to 3 μm. Depending onthe kind and characteristic of pigment and on the composition of theresin material, the content of the pigment in the inner layer 7 ispreferably about 20 to 50 wt %, more preferably about 30 to 40 wt %relative to the overall inner layer 7.

Since the inner layer 7 is formed on the outer circumference of the core30, the constituent materials of the inner layer 7 include a resinmaterial functioning as a binder to improve adhesion with the core 30,for example. Although not particularly restrictive, examples of theresin material include polysulphone, polyimide, polyether ether ketone,polyarylene ketone, polyphenylene sulfide, polyarylene sulfide,polyamideimide, polyetherimide, polyimide sulfone, polyaryl sulfone,polyaryl ether sulfone, polyester, and polyethersulfone.

Though not limited in this regard, the thickness of the inner layer 7 ispreferably e.g. 0.002 to 0.015 mm, more preferably 0.004 to 0.008 mm.

The outer layer 8 is formed on the inner layer 7. In the illustratedembodiment, the outer layer 8 is formed directly on the inner layer 7 sothat the inner surface of the outer layer directly contacts the outersurface of the inner layer 7. The outer layer 8 is preferably formed ofa material containing e.g. resin and pigment.

As an example, a fluorinated resin material is preferably used as theresin in the outer layer 8, similar to the inner layer 7. For example,polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP) orthe like can be used as the fluorinated resin material.

The pigment in the outer layer 8 may be any of inorganic pigment andorganic pigment. The inorganic pigment is preferred in view of thermalresistance during formation of the outer layer 8. The same materials asthose included in the description of the inner layer 7 can be used asthe inorganic material. Depending on the kind and characteristic of thepigment and on the composition and characteristic of a resin material,for example, the content of the pigment of the outer layer 8 ispreferably about 10 to 50 wt %, more preferably 20 to 30 wt %, of theoverall outer layer 8.

Though not particularly restrictive, the thickness of the outer layer 8is preferably 0.002 to 0.015 mm, more preferably, 0.005 to 0.010 mm.

The linear member 9A is provided or formed on the outer layer 8. Thelinear member 9A is spirally wounded around the outer layer 8 as shownin FIG. 1. In this way, the linear member 9A is provided over theoverall circumference of the second wire 3, meaning the linear member 9Aextends from the distal end of the second wire member 3 to the proximalend of the second wire member 3. In addition, the linear member 9A isnon-densely wound such that adjacent linear members are separate fromeach other. That is, axially adjacent windings of the linear member areaxially spaced apart from one another. In the present embodiment, thelinear member can be comprised of a single linear member as is the casewith the illustrated embodiment or can be comprised of plural linearmember portions. If the linear member is comprised of a number of linearmember portions 9A, the spirally wound direction of the respectivelinear member portions is the same.

The linear members 9A results in the outer surface of the second wire 3(the wire body 10) being provided with a plurality of radially outwardlyprotruding portions 34 composed of the linear members 9A and recessedportions 35 (i.e., non-protruding portions) each defined between axiallyadjacent protruding portions 34 (the linear members 9A). The pluralityof protruding portions 34 are axially spaced apart from one another. Inaddition, the protruding portions 34 extend further radially outwardlythan the recessed portions 35, meaning that the protruding portions 34are elevationally above or higher than the recessed portions 35.

The linear member 9A is preferably made of a material containing resinand pigment.

Though not limited in this regard, a fluorinated resin material is anexample of a material preferably used as the resin material in thelinear member 9A, similar to the inner layer 7. For example,polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP) orthe like can be used as the fluorinated resin material.

The pigment in the linear member 9A may be any inorganic pigment ororganic pigment. The inorganic pigment is preferred in view of thermalresistance during formation of the linear member 9A. The same materialsas those included in the description of the inner layer 7 can be used asthe inorganic material here. Depending on the kind and characteristic ofthe pigment, and the composition and characteristic of the resinmaterial, the content of the pigment of the linear member 9A ispreferably about 1 to 8 wt %, more preferably about 3 to 5 wt %, of theoverall linear member 9A.

In the guide wire 1A, the friction coefficient of the linear member 9A(the protruding portion 34) is smaller than that of the bottom 351 (anexposed portion of the outer layer 8) of the recessed portion 35. Toachieve this difference/relationship in the friction coefficients, thefollowing constituents can be included for example.

[1] Employing an arrangement in which the linear member 9A is made ofPTFE and the outer layer 8 is made of FEP

PTFE is a material having a friction coefficient smaller than that ofFEP. Thus, with the linear member 9A made of PTFE and the outer layer 8made of FEP, the friction coefficient of the protruding portion 34 issmaller than that of the bottom 351 of the recessed portion 35.

[2] Employing a construction in which the linear member 9A is made ofPTFE and the outer layer 8 is made of a material containing PTFE andpigment (or a binder resin)

If pigment or a binder resin, which is a material having a frictioncoefficient larger (i.e., greater) than that of PTFE, is blended withPTFE, the friction coefficient of the overall material composition isgreater than that of a material made of PTFE alone. Because of this,also if the linear member 9A is made of PTFE and the outer layer 8 ismade of a material containing PTFE and pigment and/or a binder resin,the friction coefficient of the protruding portion 34 is less than thatof the bottom 351 of the recessed portion 35.

[3] Employing a construction in which the linear member 9A and the outerlayer 8 are made of the same resin material, but a content rate(contained amount) of pigment in one of the resin material compositionsis different from that in the other

If the content rate of the pigment in the linear member 9A is smallerthan that in the outer layer 8, the friction coefficient of theprotruding portion 34 is smaller than that of the bottom 351 of therecessed portion 35.

With constructions such as those discussed above the frictioncoefficient of the protruding portion 34 is reliably smaller than thatof the bottom 351 of the recessed portion 35. Thus, the top 341 of theprotruding portion 34 becomes more abhesive (more slippery) than thebottom 351 of the recessed portion 35.

The guide wire 1A configured as discussed above is used, for example, bybeing inserted into the lumen 201 of the catheter 200. This state ishereinafter called “the inserted state” and an example of this state isshown in FIG. 2. In this inserted state, while a portion of the guidewire 1A projects or is exposed outside the lumen, the proximal end ofthe catheter 200 of the guide wire 1A is gripped, the guide wire 1A isshifted along its axial direction or turned around its axis. In thisway, the guide wire 1A can be operated.

As illustrated in FIG. 2, a portion of the guide wire 1A that isinserted into the lumen 201 of the catheter 200 is discussed below. Thetop 341 of each protruding portion 34 (the linear member 9A) andportions of the linear member 9A adjacent the top each having arelatively low friction coefficient come into abutment against (contactwith) the inner wall 202 of the catheter 200. In addition, the bottom351 of each recessed portion 35 having a relatively high frictioncoefficient are prevented from coming into abutment against the innerwall 202 of the catheter 200. Thus, when the guide wire 1A is operated,the tops 341 of the protruding portions 34 slide along the inner wall202 of the catheter 200, exhibiting satisfactory sliding performance.

Also, referring to FIG. 3, at a hand engaging portion (a grip portion),a fingertip 500 (finger) is inserted into the recessed portion 35.Specifically, the skin (surface) 501 of the fingertip 500 mainly comesinto abutment against (contact with) the bottom 351 of the recessedportion 35 having a relatively high friction coefficient rather thancoming into abutment against each protruding portion 34 having arelatively low friction coefficient. Thus, when the guide wire 1A isoperated, the fingertip 500 can reliably be prevented from slippingagainst the guide wire 1A. That is, a grip force (gripping force) canreliably be prevented from being lowered. Consequently, the pushabilityand torque at the hand portion can be reliably transmitted to the distalend of the guide wire 1A.

As described above, the guide wire 1A is formed with the portions whoseexternal surface exhibit or possess different friction coefficient fromeach other. Therefore, there are portions different in slidingresistance from each other depending on the counterpart abutted in theused state. That is to say, there occurs a portion having a smallersliding resistance encountered when it comes into main contact with thetop 341 of the protruding portion 34 than that encountered when it comesinto contact with the bottom 351 of the recessed portion 35.

FIG. 11 illustrates, by way of example, respective friction coefficientsof the protruding portion 34 and the recessed portion 35. A testingmethod (measuring method) for determining the respective frictioncoefficients is discussed below.

This test used a Nanotribometer (manufactured by Nanotec Corporation) asthe test equipment (measuring equipment). In this test equipment, ameasuring terminal that is adapted to come into abutment against theprotruding portion 34 and recessed portion 35 of the guide wire 1A is aterminal made of ruby having an outer diameter of 1.5 mm. The measuringterminal was pressed against the protruding portion 34 (or the recessedportion 35) at a pressing force of 50 mN, and was then shifted or movedby 0.1 mm at a sliding rate of 0.50 mm/sec. Such shifting or movementwas repeated 50 times (reciprocated 50 times). The average value of suchfriction coefficients was obtained and the average value thus obtainedwas defined as a friction coefficient of the protruding portion 34 (orthe recessed portion 35). In FIG. 11, the friction coefficient of theprotruding portion 34 is 0.024 and the friction coefficient of therecessed portion 35 is 0.048.

As illustrated in FIGS. 2-4, the protruding portions 34 are eachsemi-circular in shape (taken along a longitudinal cross-section of theguide wire or a transverse cross-section of just the linear member) sothat they are convexly curved, possessing a rounded top 341. In theinserted state, this reduces a contact area between the top 341 of theprotruding portion 34 and the inner wall 202 of the catheter 200 toreduce the friction resistance (sliding resistance), which improvessliding performance, thereby make the operability of the guide wire 1Asatisfactory.

The bottom 351 of the recessed portion 35 is formed linearly along thelongitudinal direction of the wire body 10 in a longitudinalcross-section. That is, the bottom 351 of the recessed portions 35 isconfigured to have no undulations. Thus, when the guide wire 1A isoperatively gripped, the skin 501 of the fingertip 500 reliably comesinto contact with the bottom 351 of the protruding portion 35 so as tothereby more reliably prevent the grip force from lowering when theguide wire 1A is operated.

Preferably, the bottom 351 of the recessed portion 35 is roughened by,for example, surface roughening. That is, the bottom 351 of the recessedportion 35 is formed to have a number of minute asperities. This furtherincreases the friction coefficient of each of the bottoms 351 of therecessed portions 35. Therefore, the sliding resistance between thebottoms 351 of the recessed portions 35 and the skin 501 of thefingertip 500 is increased when the guide wire 1A is operativelygripped. Thus, the fingertip 500 is reliably prevented from slippingrelative to the guide wire 1A, whereby the pushability and torque at thehand portion is reliably transmitted to the distal end of the guide wire1A.

As illustrated in FIG. 1, the protruding portion 34 is comprised of ahigh-density part 342 and a low-density part 343. The high-density part342 and the low-density part 343 are formed different from each other interms of the arrangement or density of the linear member. That is, theinterval (pitch) between the adjacent linear members 9A differs betweenthe high-density part 342 and the low-density part 343. Stateddifferently, the density per unit area of the protruding portions in thehigh-density part 342 is greater than in the low-density part 343.

The high-density part 342 is a part of the protruding portion 34 havinga higher arrangement density than that of the low-density part 343. Thehigh-density part 342 extends from the middle portion or intermediateportion of the small diameter section 33 of the second wire 3 via thetapered section 32 to the middle portion or intermediate portion of thelarge diameter section 31. In the illustrated embodiment, the distal endof the high-density part 342 is located in the middle of the smalldiameter section 33 of the second wire 3 and the proximal end of thehigh-density part 342 is located in the middle of the large diametersection 31.

The low-density part 343 is located on the distal end side of thehigh-density part 342. The low-density part 343 extends from the middleportion or intermediate portion of the large diameter section 31 to thedistal end portion of the large diameter section 31. In the illustratedembodiment, the distal end of the low-density part 343 is positioned inthe middle of the large diameter section 31.

Since the high-density part 342 and the low-density part 343 areconfigured as described above, the portion of the guide wire 1A mainlyinserted into the catheter 200 in the inserted state is such that arelatively high number of the tops 341 of the protruding portions 34 inthe high-density part 342 can (positively) be brought into abutmentagainst and slid along the inner wall 202 of the catheter 200. This canexhibit more satisfactory sliding performance. In addition, the grippedportion of the guide wire 1A is such that the bottoms 351 of therecessed portions 35 in the area of the low-density part 343 can bebrought into more preferential abutment against the fingertip 500 thanthe tops 341 of the protruding portions 34 in the low-density part 343.Thus, the grip force can be more reliably inhibited or prevented fromlowering when the guide wire 1A is operated.

As illustrated in FIG. 1, in the guide wire 1A, the occupancy of theprotruding portions 34 on the external surface of the low-density part343 is smaller than that of the recessed portions 35. This provides anadvantage that when the guide wire 1A is successively inserted from itsdistal end side (the distal end 41), even if any portion of the externalsurface of the second wire 3 is gripped, it is possible to achieve agiven or more grip force.

The protruding portion 34, i.e., the linear member 9A can be formed, forexample, as described below.

First, a masking tape is spirally wound around the core 30 formed withthe inner layer 7 and with the outer layer 8. The masking tape isspirally wound in those portions of the outer layer 8 excluding an areato be formed with the linear member 9A.

Next, the liquid resin material (hereinafter referred to as “the liquidmaterial”) to which is added the pigment is coated on (applied to) theexposed portion of the outer layer 8 where the masking tape is notwound. Examples of the coating method include a spray-used method and adipping method. Next, the coated liquid material is dried. Thereafter,the masking tape is peeled off (removed). The linear member 9A can beformed by such steps.

The linear member 9A is uniform in width along its forming direction inthe configuration illustrated in FIG. 1. However, the invention is notlimited in this regard. For example, the linear member 9A may be variedin width along its forming direction. The width of the linear member 9Ais preferably 0.1 to 1.2 mm, more preferably 0.3 to 0.9 mm. The axiallength (i.e., the length in the wire-longitudinal direction) of therecessed portion 35 is preferably 0.3 to 1.8 mm, more preferably 0.5 to1.5 mm. The height of the linear member 9A is preferably 5 to 15 μm,more preferably 7 to 13 μm. With the construction of the guide wiredescribed above, the spaced apart protruding portions 34 and interposedrecessed portions 35 form an undulating outer surface in the overallguide wire.

As illustrated in FIGS. 1 and 4, a covering layer 11 is provided at thedistal end portion of the second wire 3 (i.e., an intermediate portionof the guide wire 1A), particularly at a portion located on the outercircumference of the tapered section 32. The covering layer 11 covers adistal end side portion (the distal end portion) of the high-densitypart 342 of the protruding portions 34. In this way, the linear member9A and the outer layer 8 in the high-density part 342 are covered by thecovering layer 11. This can reduce friction with the inner wall 202 ofthe catheter 200, which facilitates insertion. Further, the frictionwith the inner wall 202 of the catheter 200 can reliably inhibit orprevent the linear member 9A and the outer layer 8 from peeling off.Thus, the covering layer 11 functions as a protection layer forprotecting the linear member 9A and the outer layer 8. Though the guidewire can be provided with a covering layer as described below, thecovering layer does not fill the recessed portions 35. Thus, even withthe covering layer 11 present, the spaced apart protruding portions 34and interposed recessed portions 35 form the undulating outer surface inthe overall guide wire and, in a longitudinal cross-section, the outerdiameter of the guide wire in the recessed portions 35 is less than theouter diameter of the guide wire at the protruding portions 34.

Although not particularly restrictive, examples of the constituentmaterial of the covering layer 11 include the fluorinated resin materialdiscussed above in the explanation of the inner layer 7.

In the portion of the guide wire formed with the covering layer 11, thetop 341 of the protruding portion 341 and the bottom 351 of the recessedportion 35 have the same friction coefficient.

FIG. 5 is a partial longitudinal cross-sectional view illustrating asecond embodiment of the guide wire disclosed here. The description ofthe second embodiment of the guide wire focuses primarily on aspects ofthe guide wire that differ from those associated with the embodimentdescribed above. Features in the second embodiment of the guide wirethat are the same as those in the earlier embodiment are identified bycommon reference numerals and a detailed description of such features isnot repeated.

The second embodiment of the guide wire is the same as the firstembodiment, except the configuration/shape of the protruding portion.

In addition to the first linear member 9A, the guide wire 1B illustratedin FIG. 5 includes another linear member (a second linear portion) 9Bextending (spirally wound) in a direction opposite to the spiral windingdirection of the first linear member 9A. The second linear member 9B ismade of the same material as that of the first linear member 9A.

With such a configuration, the second wire 3 possesses a plurality ofradially outwardly protruding portions 34 composed of the first linearmembers 9A and the second linear members 9B on the external surfacethereof, and a recessed portion 35 formed between the adjacentprotruding portions 34. Therefore, similar to the first embodiment, inthe inserted state, a portion of the guide wire 1B that is inserted intothe lumen 201 of the catheter 200 is configured as discussed below. Thetops 341 of the protruding portions 34 each having a relatively lowfriction coefficient mainly come into abutment against the inner wall202 of the catheter 200. In addition, the bottoms 351 of the recessedportions 35 each having a relatively high friction coefficient areprevented from coming into abutment against the inner wall 202 of thecatheter 200. Thus, when the guide wire 1B is operated, the tops 341 ofthe protruding portions 34 slide along the inner wall 202 of thecatheter 200, exhibiting satisfactory sliding performance. In addition,at the hand gripping portion, the fingertip 500 enters the recessedportion 35. Specifically, the skin 501 of the fingertip 500 mainly comesinto abutment against the bottom 351 of the recessed portion 35 having arelatively high friction coefficient. Thus, a grip force can reliably beinhibited or prevented from being lowered when the guide wire 1B isoperated.

In addition, the guide wire 1B (the second wire 3) is formed withintersecting portions 91 where the linear members 9A and the linearmembers 9B intersect each other. The fingertips 500 (the skin 501)gripping the guide wire 1B are tucked (seized) on the circumference(periphery) of the intersecting portion 91. Thus, the grip force can bereliably prevented from being lowered when the guide wire 1B isoperated.

The linear member 9A and the linear member 9B may be the same ordifferent from each other in friction coefficient. Examples of a methodof making the linear member 9A and the linear member 9B different infriction coefficient from each other include changing the kind of theresin material forming the linear members 9A, 9B, and changing thecontent (amount) of pigment.

The number of second linear members 9B is preferably the same as that ofthe number of first linear members 9A. That is, in this illustratedembodiment, the first and second linear members 9A, 9B are eachcomprised of a single linear member, though each could be comprised ofseveral linear member portions. However, the present invention is notlimited to this. Indeed, the number of second linear members 9B may bedifferent from the number of first linear members 9A.

FIG. 6 illustrates a third embodiment of the guide wire disclosed here.The description of the third embodiment of the guide wire focusesprimarily on aspects of the guide wire that differ from those associatedwith the embodiments described above. Features in the third embodimentof the guide wire that are the same as those in the earlier embodimentare identified by common reference numerals and a detailed descriptionof such features is not repeated.

The third embodiment of the guide wire is the same as the firstembodiment, except for the configuration of the protruding portion.

A guide wire 1C illustrated in FIG. 6 is such that the second wire 3 isformed with a plurality of ring-shaped or annular portions (linearmembers) 9C each configured to extend in the circumferential directionthereof. The ring-shaped portions 9C are each made of the same materialas that of the linear member 9A.

These ring-shaped portions 9C are spaced apart from each other in thewire-longitudinal direction. With this, the second wire 3 has aplurality of radially outwardly protruding portions 34 formed of thering-shaped portions 9C and recessed portions 35 each located betweenadjacent protruding portions 34 on the external surface of the layer 8.Thus, similar to the first embodiment, when the guide wire 1C isoperated in the inserted state, the tops 341 of the protruding portions34 slide along the inner wall 202 of the catheter 200, therebyexhibiting satisfactory sliding performance. At the hand portion, theskin 501 of the fingertip 500 comes into abutment against the bottom 351of the recessed portion 35. This can reliably inhibit or prevent thegrip force from lowering when the guide wire 1C is operated.

FIG. 7 is a partial cross-sectional longitudinal view illustrating afourth embodiment of the guide wire disclosed here. The description ofthe fourth embodiment of the guide wire focuses primarily on aspects ofthe guide wire that differ from those associated with the embodimentsdescribed above. Features in the fourth embodiment of the guide wirethat are the same as those in the earlier embodiments are identified bycommon reference numerals and a detailed description of such features isnot repeated.

The fourth embodiment is the same as the first embodiment, except forthe configuration of the protruding portion.

A guide wire 1D illustrated in FIG. 7 is configured so that the secondwire 3 includes a plurality of linear members 9D (six in the presentembodiment) extending linearly and axially along its longitudinaldirection (parallel to the central axis of the wire body). The linearmembers 9D each extend (span) from the proximal end portion of the smalldiameter section 33 of the second wire 3 to the proximal end portion ofthe large diameter section 31 of the second wire 3. Also, the linearmembers 9D are made of the same material as that of the linear member9A.

The linear members 9D are circumferentially arranged or spaced at equalintervals (at given intervals) on the outer circumference (externalsurface) of the second wire 3. With this, the second wire 3 has aplurality of axially extending radially outwardly protruding portions 34formed of the linear members 9D on the outer surface and axiallyextending recessed portions 35 each formed between adjacent protrudingportions 34. Thus, similar to the first embodiment, when the guide wire1D is operated in the inserted state, the tops 341 of the protrudingportions 34 slide along the inner wall 202 of the catheter 200,exhibiting satisfactory sliding performance. The respective protrudingportions 34 are formed of the linear members 9D extending linearly inthe wire-longitudinal direction. Therefore, when the guide wire 1D isshifted along the wire-longitudinal direction, its shifting direction isa direction where the protruding portions 34 are more easily slidable.Thus, the shifting operation of the guide wire 1D becomes easier. At thehand gripping portion, the skin 500 of the fingertip 500 abuts againstthe bottom 351 of the recessed portion 35, which can reliably inhibit orprevent the grip force from lowering when the guide wire 1D is operated.

The width of each linear member 9D is constant along the longitudinaldirection of the second wire 3. However, the guide wire here is notlimited in this regard. The width of each linear member 9D may bevaried.

In addition, the height of each linear member 9D is constant along thelongitudinal direction of the second wire 3. Once again, the guide wirehere is not limited in this regard as the height of each linear member9D may be varied.

The illustrated embodiment of the guide wire includes six linear members9D. However, other numbers of linear members may be provided. The numberof linear members 9D may be e.g., two, three, four, five, seven or more.

FIG. 8 is a partial longitudinal cross-sectional view of a fifthembodiment of the guide wire. The description of the fifth embodiment ofthe guide wire focuses primarily on aspects of the guide wire differingfrom those associated with the embodiments described above. Features inthe fifth embodiment of the guide wire that are the same as those in theearlier embodiments are identified by common reference numerals and adetailed description of such features is not repeated.

The fifth embodiment disclosed here is the same as the fourthembodiment, except for differences in the configuration of the linearmembers.

A guide wire 1E illustrated in FIG. 8 is configured such that the secondwire 3 is includes a plurality of axially extending linear members 9D(three in the present embodiment) of a relatively longer length and aplurality of axially extending linear members 9E each of a relativelyshorter length than the relatively longer linear members 9D. The linearmembers 9E of relatively shorter length are positioned between thelinear members 9D relatively longer length so that in thecircumferential direction the relatively longer linear members 9Dalternate with the relatively shorter linear members 9E. In addition,there are a plurality (four in the illustrated embodiment) of theshorter linear members 9E that are axially aligned (co-linear) with eachother. Thus, in the circumferential direction, the second wire 3includes a relatively longer linear member 9D, a set of four axially orlongitudinally aligned shorter linear members 9E, another relativelylonger linear member 9D, another set of four longitudinally alignedshorter linear members 9E, a further relatively longer linear member 9D,and a further set of four longitudinally aligned shorter linear members9E, arranged in that order. The linear members 9D, 9E provide radiallyoutwardly protruding portions.

The guide wire 1E configured as above includes a high-density part 342where both the linear members 9D and the linear members 9E arecircumferentially arranged, and a low-density part 343 where the linearmembers 9E are circumferentially omitted (absent) but the linear members9D are arranged alternately in the wire-longitudinal direction. Thus,parts of the guide wire can be formed different from each other insliding performance. With such a configuration, the configuration of theguide wire 1E is effective.

FIG. 9 is a partial longitudinal cross-sectional view illustrating asixth embodiment of the guide wire disclosed here. The description ofthe sixth embodiment of the guide wire focuses primarily on aspects ofthe guide wire that differ from those associated with the embodimentsdescribed above. Features in the sixth embodiment of the guide wire thatare the same as those in the earlier embodiment are identified by commonreference numerals and a detailed description of such features is notrepeated.

The sixth embodiment of the guide wire is the same as the firstembodiment, except for the configuration of the protruding portions.

The guide wire 1F illustrated in FIG. 9 includes a number of dome-likedots 9F arranged in a scattered manner on the second wire 3. The secondwire 3 thus comprises a plurality of radially outwardly protrudingportions 34 formed of the dots 9F on the external surface and recessedportions 35 each formed between the adjacent protruding portions or dots34. The dots 9F are each made of the same material as that of the linearmember 9A.

As with the first embodiment, when the guide wire 1F is operated in theinserted state, the tops 341 of the respective protruding portions 34slide along the inner wall 202 of the catheter 200, which exhibitssatisfactory sliding performance. At the hand gripping portion, the skin501 of the fingertip 500 abuts against the bottom 351 of the recessedportion 35, which can reliably prevent the grip force from being loweredwhen the guide wire 1F is operated.

The respective dots 9F have the same diameter in the illustratedembodiment. However, the guide wire here is not limited in this regardas the dots 9F may have different diameters.

In addition, the respective dots 9F have the same height, though theguide wire is not limited to this configuration. The dots 9F may havedifferent heights.

FIG. 10 is an enlarged longitudinal cross-sectional view illustrating aseventh embodiment of the guide wire disclosed here. The description ofthe seventh embodiment of the guide wire focuses primarily on aspects ofthe guide wire that differ from those associated with the embodimentdescribed above. Features in the seventh embodiment of the guide wirethat are the same as those in the earlier embodiment are identified bycommon reference numerals and a detailed description of such features isnot repeated.

The seventh embodiment is the same as the first embodiment, except thatthe covering layer, which covers the distal end side portion of thehigh-density part of the protruding portion, is omitted.

As shown in FIG. 10, the guide wire 1G does not include the coveringlayer like the covering layer 11 in the first embodiment. With thisconstruction, the linear members 9A and the outer layer 8 in thehigh-density part 342 are exposed. The high-density part 342 spans orextends from the tapered section 32 to the large diameter section 31 inthe second wire 3. Indeed, in this embodiment shown in FIG. 10, thehigh-density part 342 begins and ends at the same places shown inFIG. 1. In particular, the vicinity of the border portion between thetapered section 32 and the large diameter section 31 is a part where thefriction with the inner wall 202 of the catheter 200 relatively easilyoccurs when the guide wire 1G is operated in the inserted state. Sincethe high-density part 342 is located at this part, sliding performancecan reliably be inhibited or prevented from being lowered when the guidewire 1G is operated, and the linear member 9A and the outer layer 8 canreliably be inhibited or prevented from being peeled off due otherwiseto the friction.

Although the illustrated embodiments of the guide wire disclosed hereare described as above, the invention is not limited to these. Portionsof the guide wire can be replaced with other constituent parts capableof exhibiting the same function. In addition, parts or features can beadded.

The guide wire disclosed here may be a combination of two or moreconfigurations (features) in the respective or different embodiments.

The distal end member made of a resin material is arranged on the outercircumference of the distal end portion of the wire body so as to coverthe distal end portion. However, the guide wire is not limited to this.For example, a coil made of a metal material may be disposed at theouter circumference of the distal end portion of the wire body. In allthe embodiments described above, the spaced apart protruding portions 34and interposed recessed portions 35 form an undulating outer surface inthe overall guide wire. Though the guide wire can be provided with acovering layer as described, the covering layer does not fill in therecessed portions 35. Thus, the undulating outer surface of the guidewire is maintained even when the coating layer is applied. In alongitudinal cross-section of the finished guide wire, the outerdiameter of the guide wire in the recessed portions 35 is less than theouter diameter of the guide wire at the protruding portions.

A description is next given of a working example disclosed here.

WORKING EXAMPLE 1

The guide wire illustrated in FIG. 1 was manufactured in which the coreforming the wire body was made of a Ni—Ti alloy. The outer layer wasmade of PTFE, FEP, a binder resin and pigment and the linear member wasmade of PTFE and pigment. Unlike FIG. 1, the pitch of the linear memberis constant along the wire-longitudinal direction.

COMPARATIVE EXAMPLE 1

Glidewire Advantage (manufactured by TERUMO CORPORATION) was used as aguide wire. The linear member as in the first embodiment was notprovided on the external surface of this guide wire.

COMPARATIVE EXAMPLE 2

The guide wire similar to that in the first embodiment was used tomanufacture a guide wire, except that a covering layer ofpolytetrafluoroethylene (PTFE) was provided on the outer surfacesubstantially fully. Therefore the recessed portions of the ComparativeExample 2 are covered by the PTFE layer.

<Torque Test>

Torque tests (torque tests 1 to 3) described above were performed on therespective guide wires of Working Example 1 and Comparative Examples 1and 2.

Referring to FIGS. 12-14, torque tests 1 to 3 were performed using thetest equipment mentioned below. This test equipment includes a firstmember 600 formed in a circular cylinder with radius R1 and a secondmember 700 formed in a circular cylinder with a radius R2 of 20 mm. Inaddition, these members were arranged and secured so as to have avertical center-to-center distance of 50 to 70 mm and a horizontalcenter-to-center distance of 50 to 70 mm.

The first members 600 had respective radii R1 of 30 mm, 40 mm and 50 mm.These members were selectively used one by one.

(Torque Test 1)

Referring to FIG. 12, a catheter 800 (manufactured by TERUMOCORPORATION: Radifocus Catheter M) of 5 Fr. (French) was prepared, woundaround the first member 600, and installed such that both the endsthereof vertically face downwards.

Next, a single guide wire was inserted into the catheter 800 so thatopposite ends projected from respective opposite ends of the catheter800. A projecting amount L of the guide wire on the distal end side (onthe side of the second member 700) was 40 mm.

Next, in this state, the guide wire was gripped at its proximal endportion and operatively turned around the central axis of the guide wirein one direction. In this way, the easiness of turning operation wasevaluated.

The evaluation results are shown in Table 1 below. In Table 1, A denotes“easy to turn,” B “able to turn,” C “hard to turn” and D “not able toturn”. (These apply to torque tests 2 and 3.)

(Torque Test 2)

Referring to FIG. 13, a catheter 800 was prepared, allowed to extendaround the first member 600 and around the second member 700, andinstalled such that the second member 700 allows the central axes ofportions of the catheter on the distal end side and the proximal endside of the second member 700 to form an angle of 45° therebetween.

Next, a single guide wire was inserted into the catheter 800 so thatopposite ends of the guide wire projected from respective opposite endsof the catheter 800. A projecting amount L of the guide wire on thedistal end side (on the side of the second member 700) was 40 mm.

Next, in this state, the guide wire was gripped at its proximal endportion and operatively turned around the guide wire central axis in onedirection. In this way, the easiness of the turning operation wasevaluated. The evaluation results are shown in Table 1.

(Torque Test 3)

Referring to FIG. 14, a catheter 800 was prepared, allowed to extendaround the first member 600 and around the second member 700, andinstalled such that the second member 700 causes the central axes ofportions of the catheter on the distal end side and the proximal endside of then second member 700 to form an angle of 90° therebetween.

Next, a single guide wire was inserted into the catheter 800 so thatopposite ends of the guide wire projected from respective opposite endsof the catheter 800. A projecting amount L of the guide wire on thedistal end side (on the side of the second member 700) was 40 mm.

Next, in this state, the guide wire was gripped at its proximal endportion and operatively turned around the guide wire central axis in onedirection. In this way, the easiness of turning operation was evaluated.

The evaluation results are shown in Table 1.

TABLE 1 Torque test 1 Torque test 2 Torque test 3 R1 = 30 R1 = 40 R1 =50 R1 = 30 R1 = 40 R1 = 50 R1 = 30 R1 = 40 R1 = 50 [mm] [mm] [mm] [mm][mm] [mm] [mm] [mm] [mm] Working A A A A A A A A A Example 1 ComparativeA A A A A A B A A Example 1 Comparative C C C C C C D C C Example 2

As clear from Table 1, all the torque tests produced results for theguide wire of Working Example 1 that are “easy to operatively turn,”that is “excellent in operability”. This means that the guide wiresaccording to Working Example 1 are excellent in sliding performance withrespect to the catheter 800 and the grip force is reliably inhibited orprevented from being lowered when the guide wire is gripped andoperated.

On the other hand, results were obtained that the guide wires ofComparative Examples 1 and 2 are “poor in operability” or “poor inoperability according to the conditions of the torque test in somecases”.

The guide wires illustrated in FIGS. 5-10 were manufactured andsubjected to the same tests. Consequently, almost the same evaluationresults as those of the Working Example 1 were obtained by therespective guide wires.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or equivalents thereof. Thus,the detailed description above describes preferred embodiments of theguide wire disclosed, but it is to be understood that the invention isnot limited to those precise embodiments described and illustratedabove. Various changes, modifications and equivalents could be effectedby one skilled in the art without departing from the spirit and scope ofthe invention as defined in the appended claims. It is expresslyintended that all such changes, modifications and equivalents which fallwithin the scope of the claims are embraced by the claims.

1. A guide wire comprising: an elongated flexible wire body possessingan outer diameter and an external surface; the elongated flexible wirebody comprising a distal end portion and a proximal end portion; theelongated flexible wire body comprising a first constant diametersection at which the outer diameter of the elongated flexible wire bodyis a constant outer diameter; the elongated flexible wire bodycomprising a second constant diameter section at which the outerdiameter of the elongated flexible wire body is a constant outerdiameter less than the constant outer diameter of the first constantdiameter section; the elongated flexible wire body comprising a taperedsection at which the outer diameter of the elongated flexible wire bodyvaries from the constant outer diameter of the first constant diametersection to the constant outer diameter of the second constant diametersection; the tapered section being positioned axially between the firstconstant diameter section and the second constant diameter section; thefirst constant diameter section being positioned proximally of thesecond constant diameter section; the wire body comprising a pluralityof radially outward protruding portions spaced apart from one another;the protruding portions extending further radially outwardly thanportions of the outer surface of the flexible wire body surrounding theprotruding portions so that recessed portions exist between adjacentprotruding portions; the guide wire possessing an undulating outermostsurface by virtue of the protruding portions and the recessed portions;the protruding portions being located in the first constant diametersection, the tapered section, and the second constant diameter section;the protruding portions having an outermost surface made of a materialpossessing a first dynamic friction coefficient, the recessed portionshaving an outermost surface made of a material possessing a seconddynamic friction coefficient, wherein the first dynamic frictioncoefficient is smaller than the second dynamic friction coefficient;wherein the wire body comprises a core and an outer layer overlying thecore, the protruding portions overlying the outer layer, the outer layerpossessing an exposed surface which is the outermost surface of therecessed portions; and wherein the outer layer is made of a fluorinatedresin material and pigment, the protruding portions are made of afluorinated resin material and pigment, and a content rate of pigment inthe protruding portions is smaller than a content rate of pigment in theouter layer.
 2. The guide wire according to claim 1, wherein theprotruding portions in a first circumferential portion of the flexiblewire body are arranged so that a density of the protruding portions perunit area is greater than in a second circumferential portion of theflexible wire body, the first portion being located distally of thesecond portion.
 3. The guide wire according to claim 2, wherein theprotruding portions are comprised of a spirally extending linear member.4. The guide wire according to claim 3, wherein a spacing betweenaxially adjacent windings of the spirally extending linear member in thefirst circumferential portion is less than the spacing between axiallyadjacent windings of the spirally extending linear member in the secondcircumferential portion.
 5. The guide wire according to claim 2, whereinthe protruding portions are comprised of a spirally extending firstlinear member, wherein a spacing between axially adjacent windings ofthe spirally extending first linear member in the first circumferentialportion is less than the spacing between axially adjacent windings ofthe spirally extending first linear member in the second circumferentialportion, and further comprising a spirally extending second linearmember separate from the first spirally extending linear member, thespirally extending first and second linear members being wound inopposite direction.
 6. The guide wire according to claim 1, wherein theprotruding portions are spaced apart dots possessing a semi-circularshape.
 7. The guide wire according to claim 1, wherein the protrudingportions are longitudinally extending linear members extending parallelto a central axis of the wire body, adjacent ones of the linear membersbeing spaced apart from each other in a circumferential direction, eachof the linear members having a distal end and a proximal end, eachlinear member extending in an uninterrupted manner from its distal endto its proximal end, the distal end of each linear member being locatedin the first constant diameter section and the proximal end of eachlinear member being located in the second constant diameter section. 8.The guide wire according to claim 1, wherein the protruding portions arelongitudinally extending linear members extending parallel to a centralaxis of the wire body, the linear members comprising first and secondlinear members that are circumferentially spaced apart from one another,the first and second linear members each having a distal end located inthe first constant diameter section and a proximal end being located inthe first constant diameter section, the first and second linear memberseach extending in an uninterrupted manner from its distal end to itsproximal end, the linear members also comprising a plurality ofcoaxially arranged third linear members positioned between the first andsecond linear members, the third linear members being separate from oneanother and axially spaced apart from each other, the linear membersalso comprising a plurality of coaxially arranged fourth linear memberspositioned between the first and second linear members, the fourthlinear members being separate from one another and axially spaced apartfrom each other, the third linear members being circumferentially spacedapart from one another.
 9. The guide wire according to claim 1, whereinthe protruding portions are comprised of a plurality of axially spacedapart and separate ring-shaped members each extending in acircumferential direction.
 10. The guide wire according to claim 1,wherein the outermost surface of the protruding portions is rounded. 11.A guide wire comprising: a wire comprising a flexible elongate wire bodypossessing an exposed external surface; the wire body comprising aprotruding portion positioned on the external surface and anon-protruding portion positioned adjacent the protruding portion, theprotruding portion possessing an exposed outer surface; the exposedouter surface of the protruding portion is comprised of a materialpossessing a dynamic friction coefficient smaller than the dynamicfriction coefficient of a material forming the exposed external surfaceof the non-protruding portion so that the dynamic friction coefficientof the exposed outer surface of the protruding portion is smaller thanthe dynamic friction coefficient of the exposed external surface of thewire body at the non-protruding portion; and wherein the non-protrudingportion is made of a fluorinated resin material and pigment, theprotruding portion is made of a fluorinated resin material and pigment,and a content rate of pigment in the protruding portion is smaller thana content rate of pigment in the non-protruding portion.
 12. The guidewire according to claim 11, wherein a top of the protruding portionpossess an outermost surface that is rounded.
 13. The guide wireaccording to claim 11, wherein the outer surface of the flexible wirebody in the non-protruding portion extends linearly along a longitudinaldirection of the wire body as viewed in longitudinal cross-section. 14.The guide wire according to claim 11, wherein the wire body has a distalportion, an intermediate portion and a proximal portion, the exposedexternal surface of the wire body at the non-protruding portion on theintermediate portion and the exposed outer surface of the protrudingportion on the intermediate portion has the same friction coefficient,and the friction coefficient of the exposed outer surface of theprotruding portion on the proximal portion is smaller than the exposedexternal surface of the wire body at the non-protruding portion on theproximal portion.
 15. The guide wire according to claim 11, wherein theprotruding portion in a first circumferential portion of the flexiblewire body are arranged so that a density of the protruding portion perunit area is greater than in a second circumferential portion of theflexible wire body, the first portion being located distally of thesecond portion.
 16. The guide wire according to claim 11, wherein theprotruding portion is comprised of a spirally extending linear member.17. The guide wire according to claim 11, wherein the protruding portionis spaced apart dots possessing a semi-circular shape.
 18. The guidewire according to claim 11, wherein the protruding portion arelongitudinally extending linear members extending parallel to a centralaxis of the wire body, adjacent ones of the linear members being spacedapart from each other in a circumferential direction, each of the linearmembers having a distal end and a proximal end, each linear memberextending in an uninterrupted manner from its distal end to its proximalend.
 19. A guide wire comprising: an elongated flexible wire body; thewire body comprising a plurality of radially outward protruding portionsspaced apart from one another, wherein recessed portions exist betweenadjacent protruding portions; the guide wire possessing an undulatingoutermost surface by virtue of the protruding portions and the recessedportions; the protruding portions having an outermost surface made of amaterial possessing a first dynamic friction coefficient, the recessedportions having an outermost surface made of a material possessing asecond dynamic friction coefficient, wherein the first dynamic frictioncoefficient is smaller than the second dynamic friction coefficient; andwherein the recessed portions are made of a fluorinated resin materialand pigment, the protruding portions are made of a fluorinated resinmaterial and pigment, and a content rate of pigment in the protrudingportions is smaller than a content rate of pigment in the recessedportions.
 20. The guide wire according to claim 19, wherein theprotruding portions terminate in a distal direction of the guide wire ata termination point, and further comprising a distal end member coveringat least a part of the distal end portion of the wire body including adistal-most end of the wire body, the distal end member being made of aflexible material, the distal end member possessing a proximal-most endwhich is distally spaced from the termination point.
 21. The guide wireaccording to claim 19, wherein the protruding portions terminate in adistal direction of the guide wire at a termination point and whereinthe wire body is comprised of a first wire possessing a proximal end anda second wire possessing a distal end, the first wire being positioneddistally of the second wire, the proximal end of the first wire beingconnected to the distal end of the second wire at a joint, thetermination point being located proximally of the joint.
 22. The guidewire according to claim 21, wherein the first wire and the second wireare made of different materials.
 23. The guide wire according to claim1, wherein the protruding portions are semi-circular in shape takenalong a longitudinal cross-section of the guide wire.
 24. The guide wireaccording to claim 11, wherein the protruding portion is semi-circularin shape taken along a longitudinal cross-section of the guide wire. 25.The guide wire according to claim 19, wherein the protruding portionsare semi-circular in shape taken along a longitudinal cross-section ofthe guide wire.